3,213 research outputs found
Developing Feedback Based Robotic Manufacturing Method for Earth-Based Materials
Although earth-based materials have the advantage of being locally sourced and have low embodied emissions, they can have an unpredictable material behavior due to their heterogeneous composition which potentially limits their use in manufacturing. As a result, it becomes challenging to standardise and maintain quality outcomes. Moreover, current industry methods are labour-intensive and require a high level of traditional knowledge. This research explores and develops a fabrication methodology for earthen materials that is location-agnostic. It involves an array of fabrication approaches, including the development of a robotic 'Impact Printing' setup using a UR10 robot and a custom tool to pick, place, and mechanically compact earth blocks. The 'Feedback System' employs Kinect 2.0 to scan the deformation of earth materials observed during fabrication and a computational algorithm to generate accurate and adapted toolpaths for the position and compaction of earthen blocks in real-time. To push the boundaries of architectural design for traditional building materials, the study investigates the construction of a closed Nubian vault using the aforementioned techniques and tools. Through the optimization of material behavior and manufacturing processes, the research opens up a pathway for automated onsite earth construction
Role of skeletal scintigraphy in soft tissue sarcoma: Improving the diagnostic yield
Background: The presence of skeletal metastases significantly
influences the therapeutic strategy adopted for soft tissue sarcoma.
However, literature on the prevalence of skeletal metastases in soft
tissue sarcoma is limited and none of the available data is based on
the Indian patient population. Aim: To determine the prevalence of
skeletal metastases at presentation in patients of soft tissue sarcoma
and to rationalise the use of preoperative skeletal scintigraphy in
such patients. Methods and Material: Preoperative bone scans were
evaluated in 122 patients with soft tissue sarcoma (median age, 34
years; range, 4-83). The scans were classified into 3 grades: Grade 1:
metastases very likely; Grade 2: equivocal; Grade 3: normal or benign
lesion. In all the patients studied, the ability of the patient to
localize the site or sites of pain was recorded and that was correlated
with the site of metastases in scintigraphy. Result: Seventeen
(13.9%) patients had Grade 1 scan; 16 of them had bony pain that was
not readily explainable by trauma or other local factors. Ten ( 8.1%)
patients had Grade 2 scan, five of them had bony pain which was not
readily explainable by trauma or other local factors. Ninety-five
patients (77.8%) had Grade 3 scan. Of these, 9 had localised bone pain
which could be definitely associated with trauma or joint degeneration.
Conclusion: The prevalence of skeletal metastases at presentation in
patients with soft tissue sarcoma is low (13.9%). The low rates of
skeletal metastases in bone pain-free patients (0.9%) versus the high
rate in symptomatic patients (76.1%) supports the use of bone scanning
in symptomatic patients only
Rah, rah, ROS: metabolic changes caused by loss of adhesion induce cell death
The high rate of glucose utilization by cancer cells has been well characterized. Recent data suggest that when normal mammary epithelial cells are cultured under nonadherent conditions, glucose consumption decreases, ATP levels fall, and concentrations of reactive oxygen species rise. The rise in reactive oxygen species causes death of nonadherent cells, which can be suppressed with antioxidants. Nonadherent ErbB2-transformed mammary epithelial cells maintain glucose transport and antioxidant production; however, antioxidants appear to enhance anchorage-independent growth. These findings integrate aspects of glucose metabolism, anoikis suppression and antioxidant production in tumor cell biology and suggest that antioxidant therapy could stimulate tumor survival
The grapevine uncharacterized intrinsic protein 1 (VvXIP1) is regulated by drought stress and transports glycerol, hydrogen peroxide, heavy metals but not water
A MIP (Major Intrinsic Protein) subfamily called Uncharacterized Intrinsic Proteins (XIP) was recently described in several fungi and eudicot plants. In this work, we cloned a XIP from grapevine, VvXIP1, and agrobacterium-mediated transformation studies in Nicotiana benthamiana revealed that the encoded aquaporin shows a preferential localization at the endoplasmic reticulum membrane. Stopped-flow spectrometry in vesicles from the aqy-null yeast strain YSH1172 overexpressing VvXIP1 showed that VvXIP1 is unable to transport water but is permeable to glycerol. Functional studies with the ROS sensitive probe CM-H(2)DCFDA in intact transformed yeasts showed that VvXIP1 is also able to permeate hydrogen peroxide (H2O2). Drop test growth assays showed that besides glycerol and H2O2, VvXIP1 also transports boric acid, copper, arsenic and nickel. Furthermore, we found that VvXIP1 transcripts were abundant in grapevine leaves from field grown plants and strongly repressed after the imposition of severe water-deficit conditions in potted vines. The observed downregulation of VvXIP1 expression in cultured grape cells in response to ABA and salt, together with the increased sensitivity to osmotic stress displayed by the aqy-null yeast overexpressing VvXIP1, corroborates the role of VvXIP1 in osmotic regulation besides its involvement in H2O2 transport and metal homeostasis.This work was supported by European Union Funds (FEDER/COMPETE Operational Competitiveness Programme) and Portuguese national Funds (FCT-Portuguese Foundation for Science and Technology): KBBE-2012-6-3117 "Inovinne", FCOMP-01-0124-FEDER-022692 and PTDC/AGR-ALI/100636/2008. HN (SFRH/BD/74257/2010) and APM (SFRH/BD/65046/2009) were supported by PhD grants from FCT. The Interuniversity Attraction Poles Programme-Belgian Science Policy (IAP7/29) and the Belgian French community ARC11/16-036 project.info:eu-repo/semantics/publishedVersio
A unified approach to molecular epidemiology investigations: tools and patterns in California as a case study for endemic shigellosis
<p>Abstract</p> <p>Background</p> <p>Shigellosis causes diarrheal disease in humans from both developed and developing countries, and multi-drug resistance is an emerging problem. The objective of this study is to present a unified approach that can be used to characterize endemic and outbreak patterns of shigellosis using use a suite of epidemiologic and molecular techniques. The approach is applied to a California case study example of endemic shigellosis at the population level.</p> <p>Methods</p> <p>Epidemiologic patterns were evaluated with respect to demographics, multi-drug resistance, antimicrobial resistance genes, plasmid profiles, and pulsed-field gel electrophoresis (PFGE) fingerprints for the 43 <it>Shigella </it>isolates obtained by the Monterey region health departments over the two year period from 2004-2005.</p> <p>Results</p> <p>The traditional epidemiologic as well as molecular epidemiologic findings were consistent with endemic as compared to outbreak shigellosis in this population. A steady low level of cases was observed throughout the study period and high diversity was observed among strains. In contrast to most studies in developed countries, the predominant species was <it>Shigella flexneri </it>(51%) followed closely by <it>S. sonnei </it>(49%). Over 95% of <it>Shigella </it>isolates were fully resistant to three or more antimicrobial drug subclasses, and 38% of isolates were resistant to five or more subclasses. More than half of <it>Shigella </it>strains tested carried the <it>tetB</it>, <it>catA</it>, or <it>bla</it><sub>TEM </sub>genes for antimicrobial resistance to tetracycline, chloramphenicol, and ampicillin, respectively.</p> <p>Conclusion</p> <p>This study shows how epidemiologic patterns at the host and bacterial population levels can be used to investigate endemic as compared to outbreak patterns of shigellosis in a community. Information gathered as part of such investigations will be instrumental in identifying emerging antimicrobial resistance, for developing treatment guidelines appropriate for that community, and to provide baseline data with which to compare outbreak strains in the future.</p
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A mobile assisted coverage hole patching scheme based on particle swarm optimization for WSNs
Wireless sensor networks (WSNs) have drawn much research attention in recent years due to the superior performance in multiple applications, such as military and industrial monitoring, smart home, disaster restoration etc. In such applications, massive sensor nodes are randomly deployed and they remain static after the deployment, to fully cover the target sensing area. This will usually cause coverage redundancy or coverage hole problem. In order to effectively deploy sensors to cover whole area, we present a novel node deployment algorithm based on mobile sensors. First, sensor nodes are randomly deployed in target area, and they remain static or switch to the sleep mode after deployment. Second, we partition the network into grids and calculate the coverage rate of each grid. We select grids with lower coverage rate as candidate grids. Finally, we awake mobile sensors from sleep mode to fix coverage hole, particle swarm optimization (PSO) algorithm is used to calculate moving position of mobile sensors. Simulation results show that our algorithm can effectively improve the coverage rate of WSNs
Studies on an alkali-thermostable xylanase from Aspergillus fumigatus MA28
An alkalitolerant fungus, Aspergillus fumigatus strain MA28 produced significant amounts of cellulase-free xylanase when grown on a variety of agro-wastes. Wheat bran as the sole carbon source supported higher xylanase production (8,450 U/L) than xylan (7,500 U/L). Soybean meal was observed to be the best nitrogen source for xylanase production (9,000 U/L). Optimum medium pH for xylanase production was 8 (9,800 U/L), though, significant quantities of the enzyme was also produced at pH 7 (8,500 U/L), 9 (8,200 U/L) and 10 (4,600 U/L). The xylanase was purified by ammonium sulphate precipitation and carboxymethyl cellulose chromatography, and was found to have a molecular weight of 14.4 kDa with a Vmax of 980 μmol/min/mg of protein and a Km of approximately 4.9 mg/mL. The optimum temperature and pH for enzyme activity was 50 °C and pH 8, respectively. However, the enzyme also showed substantial residual activity at 60–70 °C (53–75%) and at alkaline pH 8–9 (56–88%)
Perception of stroke and knowledge of potential risk factors among Omani patients at increased risk for stroke
BACKGROUND: Previous studies have demonstrated poor knowledge of stroke among patients with established risk factors. This study aims to assess the baseline knowledge, among patients with increased risk for stroke in Oman, of warning symptoms of stroke, impending risk factors, treatment, and sources of information. METHODS: In April 2005, trained family practice residents at Sultan Qaboos University Hospital Clinics (cardiology, neurology, diabetic, and lipid clinics), using a standardised, structured, pre-tested questionnaire, conducted a survey of 400 Omani patients. These patients all demonstrated potential risk factors for stroke. RESULTS: Only 35% of the subjects stated that the brain is the organ affected by a stroke, 68% correctly identified at least one symptom/sign of a stroke, and 43% correctly identified at least one stroke risk factor. The majority (62%) did not believe they were at increased risk for stroke, and 98% had not been advised by their attending physician that their clinical conditions were risk factors for stroke. In the multivariable logistic regression analysis, lower age and higher levels of education were associated with better knowledge regarding the organ involved in stroke, stroke symptoms, and risk factors. CONCLUSION: Because their knowledge about stroke risk factors was poor, the subjects in this study were largely unaware of their increased risk for stroke. Intensive health education is needed to improve awareness of stroke, especially among the most vulnerable groups
Recurrence and mortality according to Estrogen Receptor status for breast cancer patients undergoing conservative surgery. Ipsilateral breast tumour recurrence dynamics provides clues for tumour biology within the residual breast
BACKGROUND: The study was designed to determine how tumour hormone receptor status affects the subsequent pattern over time (dynamics) of breast cancer recurrence and death following conservative primary breast cancer resection.
METHODS: Time span from primary resection until both first recurrence and death were considered among 2825 patients undergoing conservative surgery with or without breast radiotherapy. The hazard rates for ipsilateral breast tumour recurrence (IBTR), distant metastasis (DM) and mortality throughout 10 years of follow-up were assessed.
RESULTS: DM dynamics displays the same bimodal pattern (first early peak at about 24 months, second late peak at the sixth-seventh year) for both estrogen receptor (ER) positive (P) and negative (N) tumours and for all local treatments and metastatic sites. The hazard rates for IBTR maintain the bimodal pattern for ERP and ERN tumours; however, each IBTR recurrence peak for ERP tumours is delayed in comparison to the corresponding timing of recurrence peaks for ERN tumours. Mortality dynamics is markedly different for ERP and ERN tumours with more early deaths among patients with ERN than among patients with ERP primary tumours.
CONCLUSION: DM dynamics is not influenced by the extent of conservative primary tumour resection and is similar for both ER phenotypes across different metastatic sites, suggesting similar mechanisms for tumour development at distant sites despite apparently different microenvironments. The IBTR risk peak delay observed in ERP tumours is an exception to the common recurrence risk rhythm. This suggests that the microenvironment within the residual breast tissue may enforce more stringent constraints upon ERP breast tumour cell growth than other tissues, prolonging the latency of IBTR. This local environment is, however, apparently less constraining to ERN cells, as IBTR dynamics is similar to the corresponding recurrence dynamics among other distant tissue
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